|Help and Advice|
|Transit of Mercury 2016|
|Giving long exposures on a digital camera|
|Photographing star trails|
|Predicting the ISS and other satellites|
|Using a mirror to view a partial eclipse|
|Simple Guide to Viewing the Space Station|
|Choosing a Telescope|
|Tips when projecting the Sun|
|Starting to Use Your Telescope|
|Imaging with a DSLR through the telescope|
|Buying a telescope for a child|
|Photographing a partial eclipse|
A reliable variable star located in the 'bowl' of Ursa Major.
Z Ursae Majoris is a red giant star whose brightness variations are due to pulsations in its our layers. Although it is classed as a semi-regular variable, Z UMa can be relied upon to produce a good amount of brightness variation on a regular basis.
|Extreme brightness range||6.3 - 9.8|
|More typical range||6.9 - 8.7|
|Period of variation||About 6 months (longer secondary period is also present)|
|Frequency of observation||Worth checking a few times per month|
|Observe using||50mm binoculars will suffice for most of the time, but 60-80mm binoculars may be required during the deeper minima|
|Visibility||Can be observed all year round. Circumpolar|
The following charts show the location of Z Ursae Majoris.
You can follow the brightness changes of Z UMa by comparing its brightness with that of the lettered comparison stars.
The first chart, which is approx 11 degrees x 8 degrees, shows the brighter comparison stars (A to D).
The second chart, which is approx 6 degrees x 4 degrees, shows the fainter comparison stars.